Electronic camera

ABSTRACT

An electronic camera of the present invention includes: an imaging unit capturing a subject to generate an original image; a derivative image generating unit reducing resolution or color of the original image to generate a derivative image for transfer; a recording unit recording the original image and the derivative image thereon such that the original image and the derivative image get associated with each other; and a transfer unit transferring the derivative image recorded on the recording unit to an external transfer destination. In this configuration, the recording unit finds the derivative image (original image) by referring to the association with the original image (or derivative image), thereby collectively managing the original image and the derivative image. This makes it possible to prevent a user from being confused at image management due to the original image and the derivative image being the same image.

TECHNICAL FIELD OF THE INVENTION

[0001] The present invention relates to an electronic camera whichgenerates derivative images for external transfer from captured originalimages. The present invention particularly relates to an image managingtechnology, an image displaying technology, and a user interfacetechnology for these derivative images.

DESCRIPTION OF THE RELATED ART

[0002] In recent years, the pixel density of an electronic camera tendsto increase more and more. With this increase in the pixel density, afile space of an image generated in an electronic camera amounts to 1Mbyte or more even after compression.

[0003] Images generated in an electronic camera are outputted to apersonal computer, a printer, a mass memory unit, a cellular phone, adigital photograph server on the Internet, and so on when necessary.

[0004] When an image of, for example, 1 Mbyte or more per frame istransferred to such external transfer destinations, a problem of a longtransfer time arises.

[0005] Further, for example, a cellular phone or the like handles imageswith an extremely lower pixel density compared with that of imageshandled by a personal computer, a printer, and the like. Therefore, in acase where an image with substantially the same pixel density as imagesused with a personal computer or a printer is transferred to a cellularphone, the cellular phone cannot receive the image because the imagedata exceeds its data capacity, resulting in data loss.

[0006] For the purpose of solving this problem, the inventor of thepresent application has come up with an idea that a derivative imagewith a reduced data size is generated when necessary in an electroniccamera to use the derivative image for external transfer.

[0007] In this case, however, the derivative image and its originalimage from which the derivative image is generated both exist in arecording unit of the electronic camera.

[0008] This consequently doubles the number of images to be managed inthe electronic camera, and there arises a problem that management ofimages in the electronic camera may be complexed to a great extent.

[0009] In particular, since these original image and derivative imageare the same image, a user has a difficulty in clearly distinguishingthe original image and the derivative image on the small monitor screenof the electronic camera and in accurately selecting from the two. As aresult, the user may mistakenly transfer the original image instead ofthe derivative image or vice versa to the exterior.

DISCLOSURE OF THE INVENTION

[0010] In view of solving the above-described problems, it is an objectof the present invention to provide a technology for appropriatelymanaging derivative images which are generated for use of externaltransfer.

[0011] It is another object of the present invention to provide an imagedisplaying technology for distinguishing between an original image and aderivative image with ease.

[0012] It is still another object of the present invention to provide auser interface technology which achieves an easy and accuratediscrimination operation on an image to be transferred.

[0013] Hereinafter, the present invention will be explained.

[0014] (1) An electronic camera of the present invention includes: animaging unit for capturing a subject to generate an original image; aderivative image generating unit for reducing resolution or color of theoriginal image to generate derivative image(s) for transfer; a recordingunit recording the original image and the derivative image thereon insuch a manner that the original image the derivative image getassociated with each other; and a transfer unit transferring thederivative image recorded on the recording unit to an external transferdestination.

[0015] With this structure, the derivative image (or original image) canbe specified by utilizing its association with its original image (orderivative image). This can realize comprehensive image management ofthe original image and the derivative image with ease based on theoriginal-derivative image associations.

[0016] It is preferable that, for example, the recording unit managesthe derivative image (or original image) in the same way as it managesits original image (or derivative image) by making use of theassociations described above. This eliminates the necessity ofseparately managing the original image and the derivative image.

[0017] (2) In another electronic camera of the present invention, therecording unit of the electronic camera in the above description (1)includes: a folder in which the original image is recorded; and lowerfolders being under the folder hierarchically and in which thederivative images are separately recorded depending on their respectiveimage sizes, in order to manage the derivative images by size in ahierarchical manner.

[0018] Such hierarchical management enables appropriate image managementof the original image and the derivative image. Especially, using thelower folders exclusively for storing the derivative images can preventa user from mistakenly storing the original image in the lower folders,thereby enabling accurate discrimination between the original image andthe derivative image in image management.

[0019] (3) In another electronic camera of the present invention, thetransfer unit of the electronic camera in the above description (1)obtains information on the external transfer destination from theexternal transfer destination or a user, and the derivative imagegenerating unit determines an image format corresponding to theinformation on the external transfer destination to generate aderivative image according to the image format.

[0020] By structuring the electronic camera in this way, it is madepossible to properly generate derivative images of the image formatsuitable for the external transfer destination. This can furthereliminate the necessity of users' manually changing the image format ofthe derivative image every time the external transfer destination ischanged.

[0021] (4) In another electronic camera of the present invention, theelectronic camera in the above description (1) further includes an erasecontrol unit for receiving an erase command for the original image froma user. The recording unit erases the original image in compliance withthe erase command, and then retrieves and erases a recorded derivativeimage which is associated with the original image.

[0022] By structuring the electronic camera in this way, in accordanceto the erase of the original image, its corresponding derivative imageis also erased. This eliminates a disadvantage that upon erasing anoriginal image, the user forgets erasing its derivative images, leavingthem in the electronic camera. In addition, from the users' point ofview, they need not separately erase the original image and itsderivative image since what they have to pay attention to is to erasethe original image.

[0023] (5) In another electronic camera of the present invention, therecording unit of the electronic camera in the above description (1)erases a derivative image which has been transferred by the transferunit. Structuring the electronic camera in this way eliminates adisadvantage that externally transferred derivative images remain in theelectronic camera.

[0024] (6) Another electronic camera of the present invention isconfigured such that the electronic camera in the above description (1)additionally includes a storage space monitoring unit for determining anavailable storage space of the recording unit and finding a shortage inthe available storage space. The recording unit erases all or a part ofthe derivative images when the storage space monitoring unit finds ashortage in the available storage space.

[0025] It is possible to prevent the accumulation of the derivativeimages, thereby accordingly solving the shortage in the availablestorage space.

[0026] (7) Another electronic camera of the present invention ischaracterized in that the electronic camera in the above description (1)further includes a transfer control unit for receiving from a user afile transfer command for the original image, and the recording unitfile-transfers the original image in compliance with the file transfercommand and retrieves, for file-transfer, a derivative image which hasbeen recorded in association with original image.

[0027] Structuring the electronic camera in this way solves a problemthat the derivative image remains at its original position, separatelyfrom the original image after the original image is file-transferred.This also allows a user to pay attention only to the file transfer ofthe original image, eliminating the necessity for the user to performthe file transfer of the original image and the derivative imageseparately.

[0028] (8) Another electronic camera of the present invention ischaracterized in that the electronic camera in the above description (1)further includes a protect control unit for receiving from a user aprotect command for the original image, and the recording unit sets aprotect attribute on the original image in compliance with the protectcommand, and retrieves a derivative image which has been recorded inassociation with the original image to set the protect attribute on thisderivative image.

[0029] Structuring the electronic camera in this way solves a problemthat the derivative image without the protect attribute is mistakenlyerased even though its original image has the protect attribute setthereon. This eliminates the necessity for the user to set the protectattribute on the original image and the derivative image separately,allowing the user to pay attention only to the protect setting on theoriginal image.

[0030] (9) Another electronic camera of the present invention ischaracterized in that the electronic camera in the above description (1)further includes an original image erase control unit for receiving onlyan erase command for the original image from a user, in which therecording unit erases the original image in compliance with the erasecommand, and retrieves a derivative image which has been recorded inassociation with the original image, and upgrades this derivative imageto the original image.

[0031] Structuring the electronic camera in this way can prevent aproblem that the user forgets that a derivative image having no originalimage remains in the electronic camera, leaving the derivative imagetherein without processing it. Note that the recording unit preferablyupgrades a derivative image of the largest image size to an originalimage when a plurality of corresponding derivative images is present.Moreover, it is preferable that the recording unit records the originalimage to which the derivative image has been upgraded, in associationwith remaining derivative images.

[0032] (10) Another electronic camera of the present invention ischaracterized in that the imaging unit of the electronic camera in theabove description (1) selectively has a moving image capture mode inwhich a subject is captured as moving images, and the derivative imagegenerating unit generates, for the original image captured in the movingimage capture mode (namely, moving images), a derivative image byreducing resolution or color of one frame of the original image.

[0033] Such generation of the derivative image from one frame of themoving images enables reduction in processing load taken for generatingthe derivative image from the moving images. It is also made possiblethat captured moving images are not transferred immediately after thecapture, but only one frame of the derivative image is transferred for atrial instead.

[0034] (11) Another electronic camera of the present invention ischaracterized in that the imaging unit of the electronic camera in theabove description (1) selectively has a continuous capture mode in whicha subject is captured as continuous static images, in which thederivative image generating unit generates, for an original imagecaptured in the continuous capture mode (namely, plural static images),derivative images (namely, plural static images) by reducing resolutionor color of each frame of the original image.

[0035] Structuring the electronic camera in this way eliminates thenecessity for the user to generate the derivative images frame by frameseparately from the continuously shot static images. This results inrealizing a very usable electronic camera.

[0036] (12) Another electronic camera of the present invention ischaracterized in that the electronic camera in the above description (1)further includes a thumbnail generating unit generating a thumbnailimage for thumbnail display from the original image and appending thegenerated thumbnail image to the original image, and the thumbnailgenerating unit does not append the thumbnail image to the originalimage when the number of pixels of the thumbnail image is equal to orlarger than the number of pixels of the derivative image.

[0037] Not appending the thumbnail image to the original image canreduce the file size of the original image properly. Note that thederivative image is preferably used in place of the thumbnail image inthe case of not appending the thumbnail to the original image asdescribed above.

[0038] (13) Another electronic camera of the present invention includes:an imaging unit for capturing a subject to generate an original image; aderivative image generating unit for reducing resolution or color of theoriginal image to generate a derivative image for transfer; a recordingunit recording the original image and the derivative image thereon; atransfer unit transferring the derivative image recorded on therecording unit to an external transfer destination; and a control uniterasing from the recording unit a derivative image which has beentransferred to exterior by the transfer unit.

[0039] Structuring the electronic camera in this way eliminates aproblem that the derivative image which has been transferred continuesto remain in the electronic camera.

[0040] (14) Another electronic camera of the present invention ischaracterized in that the electronic camera in the above description (1)further includes a display unit displaying an image or information onthe image, wherein the display unit discriminates between the originalimage and the derivative image and decides the derivative image asnon-display.

[0041] In such a structure, not displaying (hiding) the derivative imageon the screen makes it possible to prevent, with sureness, the user frombeing confused because the original image and the derivative image beingthe same image appear on the screen. In addition, deciding thederivative image as non-display reduces the number of images to bedisplayed. This enables the user to quickly find a target image from asmall number of display images.

[0042] (15) Another electronic camera of the present invention ischaracterized in that the electronic camera in the above description (1)further includes a display unit displaying an image or information onthe image, and the display unit displays information on the image sizeof the derivative image in addition to the derivative image.

[0043] Such a structure of the electronic camera enables the user toaccurately distinguish the original image and the derivative image beingthe same image, according to the displayed image size.

[0044] (16) Another electronic camera of the present invention ischaracterized in that the electronic camera in the above description (1)further includes a display unit displaying an image or information onthe image, and the display unit displays a derivative image when theuser performs a predetermined operation during the display of theoriginal image, and displays derivative images in the order of theirimage sizes according to the user's operation when a plurality ofderivative images generated from the same original image are present.

[0045] With such a structure of the electronic camera, when thepredetermined user's operation is performed during the display of theoriginal image, its corresponding derivative image is displayed. In thiscase, first displayed is the original image and next is the derivativeimage, therefore, the user can accurately distinguish the original imageand the derivative image being the same image according to the displayorder.

[0046] Further, in a case where a plurality of derivative imagesgenerated from the same original image are present, the derivativeimages are displayed in the order of their image sizes according to theuser's operation. This enables the user to accurately decide a magnituderelation of plural images being the same image, according to the displayorder.

[0047] (17) Another electronic camera of the present invention ischaracterized in that the electronic camera in the above description (1)further includes a display unit displaying an image or information onthe image, and the display unit, upon deciding the original image asnon-display, decides a derivative image generated from this originalimage as non-display.

[0048] Structuring the electronic camera in this way can preventoccurrence of a problem that a derivative image of the original image asnon-display is displayed. Further, the user need not set non-displaytwice separately for the original image and its derivative image beingthe same image, therefore, the user can save his/her labor.

[0049] (18) Another electronic camera of the present invention ischaracterized in that the electronic camera in the above description (1)further includes a display unit displaying an image or information onthe image, and the display unit discriminates between the original imageand the derivative image and does not display the original image and thederivative image concurrently on the screen.

[0050] In such a structure, the original image and the derivative imagebeing the same image are not displayed together on the same screen,which can prevent the user from being confused because of his/herinability to distinguish the images. Further, the original image and thederivative image being the same image are not displayed at the same timeso that many different images can be concurrently displayed. Thisenables the user to quickly find a target image from various images in adisplay list.

[0051] (19) Another electronic camera of the present invention ischaracterized in that the electronic camera in the above description (1)further includes a slide display unit automatically displaying aplurality of images in sequence, and the slide display unit separatesthe plurality of images into original images and derivative images toautomatically display either of the original images and the derivativeimages.

[0052] Structuring the electronic camera in this way can preventredundant slide displays of the original images and the derivativeimages being the same image. As a result, the user can look through allimages in a relatively short time, or he/she can take his/her time asmuch as he/she wants to look through all images since it is madepossible to elongate the display time per frame without elongating thetotal display time.

[0053] (20) In another electronic camera of the present invention, thetransfer unit of the electronic camera in the above description (1) hasa function of transferring the original image in addition to a functionof transferring the derivative image. This electronic camera furtherincludes a transfer setting unit setting a flag on an image designatedby a user's input, the flag indicating a transfer candidate of thetransfer unit. Specifically, the derivative image generating unit ofthis electronic camera, when generating the derivative image from theoriginal image having a flag thereon, removes the flag from thisoriginal image and sets the flag on the generated derivative image.

[0054] Such a structure enables the user to freely select an image to betransferred by performing the following operations {circle over (1)} and{circle over (2)}.

[0055] {circle over (1)} The user selects an image to be transferredfrom original images and temporarily sets the flag on the selectedoriginal image.

[0056] {circle over (2)} The user thereafter selects from the originalimages a to-be-transferred image with reduced file space, therebygenerating a derivative image.

[0057] At this time, the electronic camera shift the flag from theoriginal image to the derivative image generated in the operation{circle over (2)}. On the other hand, the original image continues tohave the flag in case where the derivative image is not generated fromthe original image. Performing the operations {circle over (1)} and{circle over (2)} enables the user to set the flag on either theoriginal image or the derivative image when necessary.

[0058] The operations {circle over (1)} and {circle over (2)} are bothintended for the original image. Therefore, the user need not payattention to the derivative image when performing these operations, andcan set the flag mainly on original images by an intuitive and simpleoperation.

[0059] (21) Another electronic camera of the present invention is sostructured that the transfer unit of the electronic camera in the abovedescription (1) further has a function of transferring the originalimage in addition to a function of transferring the derivative image.This electronic camera further includes a transfer setting unit settinga flag on an image designated by user's input, the flag indicating atransfer candidate of the transfer unit.

[0060] Specifically, the transfer setting unit of this electroniccamera, when the original image selected by the user's input has itsderivative image, sets the flag not on the original image but on thederivative image.

[0061] Such a structure enables the user to freely select an image to betransferred by performing the following operations {circle over (3)} and{circle over (4)}.

[0062] {circle over (3)} The user selects from original images an imageto be transferred with reduced file space and temporarily generates aderivative image.

[0063] {circle over (4)} The user thereafter selects an image to betransferred from the original images and sets the flag on the selectedoriginal image.

[0064] At this time, the electronic camera shifts, at the operation{circle over (4)}, the flag from the original image to the derivativeimage generated in the operation. On the other hand, the original imagecontinues to have the flag when the derivative image is not generatedfrom the original image in the operation {circle over (3)}. The user canallot the flag to the original image and the derivative image whennecessary by performing the operations {circle over (3)} and {circleover (4)}.

[0065] The operations {circle over (3)} and {circle over (4)} are, bothintended for the original images. Therefore, the user need not payattention to the derivative image when performing these operation, andcan set the flag mainly on original images by an intuitive and simpleoperation.

[0066] Note that it is more preferable to carry out both the inventionsdescribed in (20) and (21) together. In this case, the user is allowedto carry out either the above operations {circle over (1)} and {circleover (2)} or operations {circle over (3)} and {circle over (4)}. Also,performing the above operations {circle over (1)} and {circle over (2)}in a reverse order is equivalent to performing the operations {circleover (3)} and {circle over (4)}. In other words, by combining both ofthe inventions in (20) and (21), the user is allowed to execute theaforesaid operations {circle over (1)} and {circle over (2)} in anyorder. This enables the user to set the flag on the original andderivative images more freely without taking the operation order intoaccount.

[0067] (22) Another electronic camera of the present invention is sostructured that the transfer unit of the electronic camera in the abovedescription (1) further has a function of transferring the originalimage in addition to a function of transferring the derivative image.This electronic camera further includes: a transfer setting unit settinga flag on an image designated by user's input, the flag indicating atransfer candidate of the transfer unit; and an erase unit erasing animage designated by a user's input.

[0068] Especially, the transfer setting unit of this electronic cameraerases, in response to the erase of the original image, a derivativeimage generated from this original image, and removes the flag from thederivative image.

[0069] With such a structure, the user need not remove the flags ofremaining derivative images in another time after erasing the originalimage, and can operate the electronic camera in a simpler manner.

[0070] (23) Another electronic camera of the present invention is sostructured that the transfer unit of the electronic camera in the abovedescription (1) further has a function of transferring the originalimage in addition to a function of transferring the derivative image.This electronic camera further includes: a transfer setting unit settinga flag on an image designated by user's input, the flag indicating atransfer candidate of the transfer unit; and an erase unit erasing animage designated by user's input.

[0071] Especially, the transfer setting unit of this electronic camera,when the derivative image having the flag set thereon is erased, setsthe flag on an original image from which the derivative image isgenerated.

[0072] With such a structure, when the user wants to return the flag tothe original image from the derivative image, he/she should first erasean unnecessary derivative image which is no longer a candidate of thetransfer. By this user's operation, the electronic camera shifts theflag from the derivative image to the original image. Therefore, theuser need not shift the flag explicitly, and can operate the electroniccamera in a simpler way.

[0073] (24) Another electronic camera of the present invention is sostructured that the transfer unit of the electronic camera in the abovedescription (1) further has a function of transferring the originalimage in addition to a function of transferring the derivative image.This electronic camera further includes a transfer setting unit settinga flag on an image designated by user's input, the flag indicating atransfer candidate of the transfer unit.

[0074] Especially, the transfer setting unit of this electronic camerasets the flag on all original images with print information,irrespective of whether or not these original images have theirderivative images.

[0075] The original images having print information are likely to beused for printing purpose at their external transfer destinations. Forthe printing use, the original image having large image information ismore preferable in view of image quality than the derivative image withreduced file space. Hence, setting the flag on the original imageshaving the print information as described above can surely improve theprint image quality at the external transfer destination.

BRIEF DESCRIPTION OF THE DRAWINGS

[0076] The above-described objects and other objects of the presentinvention will be made apparent with reference to the followingdescription and the attached drawings.

[0077]FIG. 1(a) and FIG. 1(b) are views each showing an externalappearance of an electronic camera 11;

[0078]FIG. 2 is a block diagram explaining the configuration of theelectronic camera 11;

[0079]FIG. 3 is a flowchart (1/2) explaining a derivative imagegenerating process;

[0080]FIG. 4 is a flowchart (2/2) explaining the derivative imagegenerating process;

[0081]FIG. 5 is a flowchart showing a process routine of filemanipulation;

[0082]FIG. 6 is a flowchart showing a derivative image generatingprocess in a second embodiment:

[0083]FIG. 7 is a flowchart explaining the operation performed in a fullscreen display mode in a third embodiment;

[0084]FIG. 8 is a flowchart explaining the operation performed in athumbnail display mode;

[0085]FIG. 9 is a view showing a display screen image in the full screendisplay mode;

[0086]FIG. 10 is a view showing a display screen image in the thumbnaildisplay mode;

[0087]FIG. 11 is a flowchart explaining the operation performed in afull screen display mode in a fourth embodiment;

[0088]FIG. 12 is a view showing a display screen image in the fullscreen display mode:

[0089]FIG. 13 is a flowchart explaining the operation performed in aslide display mode in the fourth embodiment;

[0090]FIG. 14 is a flowchart explaining the operation performed in afull screen display mode;

[0091]FIG. 15 is a flowchart explaining the operation performed in athumbnail display mode; and

[0092]FIG. 16 shows thumbnail display.

BEST MODE FOR CARRYING OUT THE INVENTION

[0093] Hereinafter, embodiments according to the present invention willbe explained with reference to the drawings.

[0094] <<First Embodiment>>

[0095] A first embodiment is an embodiment of an electronic cameracorresponding to the inventions of claims 1, 4, 5, 7 to 9, 12, and 13.

[0096] [Configuration Description of Electronic Camera]

[0097]FIG. 1(a) and FIG. 1(b) are views each showing an externalappearance of this electronic camera 11. Note that FIG. 1(a) is a topview of the electronic camera 11, and FIG. 1(b) is a rear view of theelectronic camera 11. FIG. 2 is a block diagram explaining the internalconfiguration of the electronic camera 11.

[0098] Hereinafter, the configuration of the electronic camera 11 willbe explained with reference to these FIG. 1 and FIG. 2.

[0099] First, a lens 12 is attached to the electronic camera 11. Animage sensor 13 is disposed in an image space of this lens 12. Thisimage sensor 13 is controlled by a timing generator 13 a and captures asubject. The image captured by this image sensor 13 (namely, an originalimage) is digitized by an image processing unit 14 and an A/D convertingunit 15, and thereafter, given to a digital signal processor(hereinafter, referred to as a DSP) 16. This DSP 16 is connected to abuffer memory 1 8 and a memory card 19 via a data bus 17. The DSP 16performs two-dimensional image processing, image compression processing,and so on for the original image while exchanging image data with thisbuffer memory 18. The original image processed in the DSP 16 is recordedon the memory card 19 in an EXIF file format.

[0100] Meanwhile, the aforesaid timing generator 13 a, image processingunit 14, DSP 16, buffer memory 18, and memory card 19 are connected to amicroprocessor (hereinafter, referred to as an MPU) 21 via a system bus20 for control and data transfer.

[0101] To this MPU 21, connected are a release button 22, a cross button23, a menu button 24, a command dial 25, a zoom button 26, a displayswitch button 27, a transfer button 28, a derivative image generatingbutton 29, an enter key 29 a, and an erase button 29 b.

[0102] Note that the aforesaid cross button 23 is constituted offour-direction keys consisting of an up key 23 a, a down key 23 b, aleft key 23 c, and a right key 23 d.

[0103] A frame memory 30 is connected to the aforesaid system bus 20.Image data in this frame memory 30 is displayed on a liquid crystaldisplay unit 31 provided on a rear face of the electronic camera 11.

[0104] To the aforesaid system bus 20, further connected is an interface32 transferring an image having a flag, to an external transferdestination in response to the operation to the transfer button 28.

[0105] [Relation with the Invention]

[0106] Hereinafter, the relation between the inventions and the firstembodiment will be explained. It should be noted that the relation hereonly illustrates one interpretation for reference and is not intended tolimit the present invention more than necessary.

[0107] An imaging unit described in the claims corresponds to the imagesensor 13, the timing generator 13 a, the image processing unit 14, theA/D converting unit 15, and the DSP 16.

[0108] A derivative image generating unit described in the claimscorresponds to ‘a derivative image generating function’ of the MPU 21(or the DSP 16).

[0109] A recording unit described in the claims corresponds to ‘afunction of file management of the memory card 19’ of the MPU 21.

[0110] A transfer unit described in the claims corresponds to theinterface 32.

[0111] An erase control unit described in the claims corresponds to ‘afunction of receiving an erase command for the original image from auser's operation or the like of the cross button 23’ of the MPU 21.

[0112] A transfer control unit described in the claims corresponds to ‘afunction of receiving a file transfer command for an original image froma user's operation or the like of the cross button 23’ of the MPU 21.

[0113] A protect control unit described in the claims corresponds to ‘afunction of receiving a protect command for an original image from auser's operation or the like of the cross button 23’ of the MPU 21.

[0114] An original image erase control unit described in the claimscorresponds to ‘a function of receiving an erase command for only anoriginal image from a user's operation or the like of the cross button23’ of the MPU 21.

[0115] A thumbnail generating unit described in the claims correspondsto ‘a function of generating a thumbnail image to append it to a fileheader of an original image’ of the MPU 21 (or the DSP 16).

[0116] A control unit described in the claims corresponds to ‘a functionof erasing from the memory card 19 a derivative image which has beentransferred’ of the MPU 21.

[0117] [Description on Derivative Image Generating Process]

[0118]FIG. 3 and FIG.4 are flowcharts explaining a derivative imagegenerating process. Note that this process starts as a part of processesin response to pressing of the down key 23 b. Hereinafter, thederivative image generating process will be explained following thesteps in FIG. 3 and FIG. 4.

[0119] Step S1: When a user presses down the down key 23 b, the MPU 21first determines a current operation mode of the electronic camera 11.

[0120] Here, when the current operation mode is a quick review mode (amode to display on the liquid crystal display unit 31 an imageimmediately after being captured) or a reproduction mode (a mode toreproduce an image in the memory card 19 for display on the liquidcrystal display unit 31), the MPU 21 shifts its operation to Step S2.

[0121] On the other hand, in the case where the current operation modeis of other operation modes, the MPU 21 shifts its operation to StepS14.

[0122] Step S2: The MPU 21 determines a current display status of theliquid crystal display unit 31.

[0123] When the original image is displayed on the full screen, the MPU21 shifts its operation to Step S3.

[0124] On the other hand, in the case where the liquid crystal displayunit 31 has other display status (a 1/4 screen display, a thumbnaildisplay, a derivative image display, or the like), the MPU 21 shifts itsoperation to Step S14.

[0125] Step 3: The MPU 21 obtains information on an available storagespace of the memory card 19.

[0126] Here, when the storage space currently available is too small tostore a new derivative image, the MPU 21 gives up generating a newderivative image and shifts its operation to Step S14.

[0127] On the other hand, when the storage space currently available islarge enough to store the derivative image, the MPU 21 shifts itsoperation to Step 4.

[0128] Step S4: The MPU 21 overlappinly displays the followingconfirmation menu on a display image on the liquid crystal display unit31.

[0129] Header “Generate a derivative image?”

[0130] Option {circle over (1)} Yes (default option)

[0131] Option {circle over (2)} No

[0132] Option {circle over (3)} Change reduction size

[0133] Step S5: The MPU 21 monitors a user's operation to the crossbutton 23 to receive a selected one of the above options {circle over(1)}) to {circle over (3)}.

[0134] Specifically, a user hits the right key 23 d once, determiningselection of the option {circle over (1)}. In this case, the MPU 21shifts its operation to Step S8.

[0135] The user hits the right key 23 d once after hitting the down key23 b once, determining selection of the option {circle over (2)}. Inthis case, the MPU 21 stops generating a new derivative image to shiftsits operation to Step S14.

[0136] Meanwhile, the user hits the right key 23 d once after hittingthe down key 23 b twice, determining selection of the option {circleover (3)}. In this case, the MPU 21 shifts its operation to Step S6.

[0137] Step S6: The MPU 21 additionally displays the followingconfirmation menu on the display image on the liquid crystal displayunit 31.

[0138] Header “Change reduction size”

[0139] Option {circle over (1)} 640×480 (default at the shipping time)

[0140] Option {circle over (2)} 320×240

[0141] Option {circle over (3)} 160×120

[0142] Option {circle over (4)} 96×72

[0143] Step S7: The MPU 21 monitors the user's operation to the crossbutton 23 to receive the selection and determination of the image size(reduction size) of the derivative image. The MPU 21 uses the image sizedetermined here as a default thereafter. After this operation, the MPU21 shifts its operation back to Step S4.

[0144] Step S8: The MPU 21 searches files in the memory card 19 todetermine whether or not a derivative image to be generated alreadyexists.

[0145] When the derivative image to be generated already exists here,the MPU 21 shifts its operation to Step S9.

[0146] On the other hand, when the derivative image to be generated doesnot exist, the MPU 21 shifts its operation to Step S11.

[0147] Step S9: The MPU 21 overlappingly displays the followingconfirmation menu on the display image on the liquid crystal displayunit 31.

[0148] Header “A derivative image already generated. Overwrite?”

[0149] Option {circle over (1)} Yes

[0150] Option {circle over (2)} No (default option)

[0151] Option {circle over (3)} Change reduction size

[0152] Step S10: The MPU 21 monitors the user's operation to the crossbutton 23 to receive a selected one of the above options {circle over(1)} to {circle over (3)}.

[0153] Specifically, the user hits the right key once, determiningselection of the option {circle over (2)}. In this case, the MPU 21stops generating a new derivative image to shift its operation to StepS14.

[0154] The user hits the right key 23 d once after hitting the down key23 b once, determining selection of the option {circle over (3)}. Inthis case, the MPU 21 shifts its operation to Step S6.

[0155] Meanwhile, the user hits the right key 23 d once after hittingthe up key 23 a once, determining selection of the option {circle over(1)}. In this case, the MPU 21 shifts its operation to Step S11.

[0156] Step 11: In the case of the reproduction mode, the MPU 21 readsout from the memory card 19 a compressed file of the original imagecurrently displayed on the liquid crystal display unit 31 to store thiscompressed file in the buffer memory 18. The DSP 16 expands thiscompressed file to develop the original image in the buffer memory 18.

[0157] On the other hand, in the case of the quick review mode, theoriginal image immediately after being captured has been developed inthe buffer memory 18 by the MPU 21.

[0158] The MPU 21 (or the DSP 16) performs resolution-conversion on thisoriginal image in the buffer memory 18 to have an image of a defaultimage size to generate a derivative image.

[0159] The DSP 16 compresses this derivative image to, for example,about {fraction (1/16)} irrespective of the compressibility of theoriginal image.

[0160] The MPU 21 copies header information of the original image,appends it to the compressed data of the derivative image to generate acompressed file in the E(IF file format.

[0161] Further, the MPU 21 replaces an initial letter of a file name“DSCN * * * .jpg” of the original image with a letter (for example, “S”or the like) according to the image size to create a file name of thederivative image. The associations between the original image and thederivative image are made according to the file name rule.

[0162] The MPU 21 records thus generated file of the derivative image inthe same folder as the original image in the memory card 19.

[0163] Step S12: The MPU 21 compares the number of pixels of a thumbnailimage appended in the file of the original image with the number ofpixels of the derivative image newly generated.

[0164] When the number of the pixels of the thumbnail image is equal toor larger than the number of the pixels of the derivative image here,the MPU 21 shifts its operation to Step S13.

[0165] On the other hand, when the number of the pixels of the thumbnailimage is smaller than the number of the pixels of the derivative image,the MPU 21 shifts its operation to Step S14.

[0166] Step S13: The MPU 21 erases the thumbnail image from the file ofthe original image to reduce a file space of the original image.Thereafter, when the thumbnail image of the original image is required,the derivative image is used as a substitute for the thumbnail image.

[0167] Step S14: The MPU 21 calls other process routines which are to beexecuted when the down key 23 b is pressed down.

[0168] Through the operations explained above, the derivative imagegenerating process is completed.

[0169] [Description on File Manipulation of Images]

[0170]FIG. 5 is a flowchart showing a process routine of filemanipulation. Hereinafter, the file manipulation to images will beexplained following the steps shown in FIG. 5.

[0171] Step S18: The user first switches the mode of the electroniccamera 11 to the reproduction mode, and selects on the liquid crystaldisplay unit 31 an original image as an object of the file manipulation.

[0172] Step S19: When the original image as the object of themanipulation is selected, the MPU 21 changes the initial letter of thefile name of this original image to create the file name of a derivativeimage. The MPU 21 searches the memory card 19 for the file name of thederivative image and determines whether or not the concerning derivativeimage exists.

[0173] Step S20: Next, the MPU 21 monitors the user's operation to themenu button 24 and the transfer button 28.

[0174] When the transfer button 28 is pressed down here, the MPU 21shifts its operation to Step S21.

[0175] On the other hand, when the menu button 24 is pressed down, theMPU 21 shifts its operation to Step S22.

[0176] Step S21: When the original image as the object of themanipulation has a derivative image, the MPU 21 transfers thisderivative image to a preset external transfer destination via theinterface 32. Upon completion of the transfer operation, the MPU 21erases from the memory card 19 the derivative image which has beentransferred, to thereby increase an available storage space of thememory card 19.

[0177] Meanwhile, when the original image as the object of themanipulation does not have any derivative image, the original image istransferred as it is to the external transfer destination via theinterface 32.

[0178] After such file manipulation, the MPU 21 completes the filemanipulation process routine.

[0179] Step S22: The MPU 21 displays a menu screen on the liquid crystaldisplay unit 31 in response to the menu button 24 being pressed down.The user operates the cross button 23 referring to the menu screen onthe liquid crystal display unit 31 to input a desired file manipulationcommand.

[0180] Step S23: When the user selects a file erase command to theoriginal image, the MPU 21 shifts its operation to Step S24. In othercases, the MPU 21 shifts its operation to Step S25.

[0181] Step S24: The MPU 21 erases from the memory card 19 the originalimage as the object of the manipulation. Note that, when the originalimage as the object of the manipulation has a derivative image, the MPU21 erases this derivative image together. After such file manipulation,the MPU 21 finishes the file manipulation process routine.

[0182] Step S25: When the user selects a file transfer command to theoriginal image, the MPU 21 shifts its operation to Step S26. In othercases, the MPU 21 shifts its operation to Step S27.

[0183] Step S26: The MPU 21 file-transfers the original image as theobject of the manipulation to a folder designated by the user. Notethat, when the original image as the object of the manipulation has aderivative image, the MPU 21 file-transfers this derivative imagetogether. After such file manipulation, the MPU 21 finishes the filemanipulation process routine.

[0184] Step S27: When the user selects a protect command for theoriginal image, the MPU 21 shifts its operation to Step S28. In othercases, the MPU 21 shifts its operation to Step S29.

[0185] Step S28: The MPU 21 appends a protect attribute to the file ofthe original image as the object of the manipulation. Note that, whenthe original image as the object of the manipulation has a derivativeimage, the MPU 21 appends the protect attribute to the file of thisderivative image as well. After such file manipulation, the MPU 21finishes the file manipulation process routine.

[0186] Step S29: When the user selects an erase command to only theoriginal image, the MPU 21 shifts its operation to Step S30. In othercases, the MPU 21 finishes the file manipulation process routine.

[0187] Step S30: The MPU 21 erases the file of the original image as theobject of the manipulation from the memory card 19. Note that, when theoriginal image as the object of the manipulation has a derivative image,the MPU 21 changes the file name of this derivative image to the filename of the original image, thereby upgrading the derivative image tothe original image. After such file manipulation, the MPU 21 finishesthe file manipulation process routine.

[0188] Through the operations explained above, the file manipulationprocess is completed.

[0189] [Effect and so on of First Embodiment]

[0190] As described above, in the first embodiment, a new derivativeimage for transfer is generated by reducing the resolution of theoriginal image. The MPU 21 changes the initial letter “D” of the filename of the original image to the initial letter “S” or the like for thederivative image to generate the file name of the derivative image. Theoriginal image and the derivative image are recorded on the memory card19 in such a manner that both the images get associated with each otherby the file name rule.

[0191] Therefore, by tracing back the associations by this file namerule, the file manipulation done to the original image can beautomatically applied to its derivative image. As a result, the userneed not separately perform file manipulation for the original image andthe derivative image, which realizes saving labor taken for managing thederivative image.

[0192] Especially, in the first embodiment, in response to the erase ofthe original image, its corresponding derivative image is erasedtogether. This eliminates a problem that an unnecessary derivative imagecontinues to remain on the memory card 19 and occupies a memory spaceeven after the original image is erased.

[0193] Further, in the first embodiment, the derivative image is erasedin response to the completion of the external transfer of the derivativeimage. This eliminates a problem that the derivative image that has beentransferred continues to remain in the electronic camera and occupiesthe memory space of the memory card 19.

[0194] Moreover, in the first embodiment, in response to the filetransfer of the original image, its corresponding derivative image isalso file-transferred. This eliminates a problem that the derivativeimage exists separately from the original image after the file transferof the original image.

[0195] In addition, in the first embodiment, in accordance with theprotect setting (erase prevention setting) of the original image, theprotect setting is set on its corresponding derivative image. Therefore,the user need not set the protect setting separately on the originalimage and on the derivative image, which makes it possible to savehis/her time and labor.

[0196] Further, in the first embodiment, when only the original image iserased, its corresponding derivative image is upgraded to the originalimage. This can prevent a disadvantage that the user does not notice thederivative image whose original image does not exist remaining on thememory card 19 and leaves it unprocessed.

[0197] Moreover, in the first embodiment, if the number of the pixels ofthe thumbnail image is equal to or larger than the number of the pixelsof the derivative image, the thumbnail image is erased from the file ofthe original image. This can reduce the file size of the original imageby the file size of the thumbnail image.

[0198] Next, another embodiment will be explained.

[0199] <<Second Embodiment>>

[0200] A second embodiment describes an electronic camera correspondingto the inventions of claims 1 to 13. Note that the configuration of theelectronic camera in the second embodiment is the same as that in thefirst embodiment (FIG. 1 and FIG. 2), and therefore, the configurationdescription thereof will be omitted here. Further, description on theoperations similar to those of the first embodiment (file manipulationto the images, suspension of thumbnail image appending, and so on) willbe omitted here in order to avoid repetition.

[0201] [Relation with the Invention]

[0202] Hereinafter, the relation between the inventions and the secondembodiment will be explained. Note that the relation here onlyillustrates one interpretation for reference, and is not intended tolimit the present invention more than necessary.

[0203] An imaging unit described in the claims corresponds to an imagesensor 13, a timing generator 13 a, an image processing unit 14, an A/Dconverting unit 15, and a DSP 16.

[0204] A derivative image generating unit described in the claimscorresponds to ‘a function of generating a derivative image’ of an MPU21 (or the DSP 16).

[0205] A recording unit described in the claims corresponds to ‘afunction of file management of a memory card 19’ of the MPU 21.

[0206] A transfer unit described in the claims corresponds to aninterface 32.

[0207] A storage space monitoring unit described in the claimscorresponds to ‘a function of monitoring an available storage space ofthe memory card 19’ of the MPU 21.

[0208] A control unit described in the claims corresponds to ‘a functionof erasing from the memory card 19 a derivative image which has beentransferred’ of the MPU 21.

[0209] [Description on Derivative Image Generating Process]

[0210]FIG. 6 is a flowchart showing a derivative image generatingprocess characterizing the second embodiment.

[0211] Hereinafter, the derivative image generating process will beexplained following the steps shown in FIG. 6.

[0212] Step S40: A user first operates a cross button 23, similarly tothe first embodiment, to give a derivative image generating command tothe MPU 21.

[0213] Step S41: The MPU 21 obtains information on an available storagespace of the memory card 19.

[0214] Step S42: The MPU 21 determines whether or not the availablestorage space of the memory card 19 is large enough to store aderivative image.

[0215] When the available storage space is too small to store thederivative image here, the MPU 21 shifts its operation to Step S42.

[0216] On the other hand, when the available storage space is largeenough to store the derivative image, the MPU 21 shifts its operation toStep S43.

[0217] Step S43: The MPU 21 erases from the memory card 19 a part or allof existing derivative images to secure a memory space in the memorycard 19.

[0218] Step S44: The MPU 21 communicates with an external transferdestination via the interface 32 to obtain information on the externaltransfer destination (incidentally, information on what kind of devicethe external transfer destination is may also be obtained through auser's input).

[0219] Step S45: The MPU 21 determines an image format (for example,image size, a screen aspect ratio, the number of colors, and so on) ofthe derivative image appropriate for the external transfer destinationin accordance with the information on the external transfer destination.

[0220] Step S46: The MPU 21 determines the type of an original imagefrom which the derivative image is generated.

[0221] When the original image is a one-frame image captured in asingle-shot capture mode here, the MPU 21 shifts its operation to StepS47.

[0222] When the original image is constituted of moving images capturedin a moving image capture mode, the MPU 21 shifts its operation to StepS48.

[0223] On the other hand, when the original image is a group of staticimages captured in a continuous capture mode, the MPU 21 shifts itsoperation to Step S49.

[0224] Step S47: The MPU 21 converts the original image (the one-framestatic image here) to the image format determined in Step S45 togenerate the derivative image. After this operation, the MPU 21 shiftsits operation to Step S50.

[0225] Step S48: The MPU 21 extracts a first frame of the original image(the moving images here).

[0226] The MPU 21 converts this first frame into the image formatdetermined in Step S45 to generate the derivative image. After thisoperation, the MPU 21 shifts its operation to Step S50.

[0227] Step S49: The MPU 21 converts each frame of the original image(the plural static images here) into the image format determined in StepS45 to generate the plural derivative images. After this operation, theMPU 21 shifts its operation to Step S50.

[0228] Step S50: The MPU 21 determines whether or not a lower foldercorresponding to the image size of the derivative image exists in afolder of the original image.

[0229] When the lower folder does not exist here, the MPU 21 shifts itsoperation to Step S51.

[0230] On the other hand, when the lower folder exists, the MPU 21shifts its operation to Step S52.

[0231] Step S51: The MPU 21 makes a lower folder exclusively for theimage size of the derivative image under a hierarchy of the originalimage folder in the memory card 19.

[0232] Step S52: The MPU 21 stores a file of the derivative image in thelower folder exclusively for the image size.

[0233] Through the above-described operations, the derivative imagegenerating process is completed.

[0234] [Effect and so on of Second Embodiment]

[0235] In the second embodiment, the same effect as that in the firstembodiment is obtainable as described above.

[0236] In addition, in the second embodiment, the lower folder is madefor each image size of the derivative image in the folder of theoriginal image, and the derivative images are stored therein, beingclassified by the image size. This enables efficient image management ofthe original images and the derivative images based on the hierarchicalfolders.

[0237] Further, in the second embodiment, the image format appropriatefor the external transfer destination is determined based on theinformation on the external transfer destination, and the derivativeimage is generated so as to conform to the image format. Consequently,the user need not change the image format or the like for every externaltransfer destination. Moreover, a suitable derivative image for theexternal transfer destination can be surely generated.

[0238] Moreover, in the second embodiment, all or a part of thederivative images are erased when the memory card 19 does not have asufficient available storage space. In this case, a shortage in theavailable storage space is compensated by the file space of the erasedderivative images, so that it is made possible to increase the number ofrecordable frames of the electronic camera with efficiency.

[0239] Note that when the memory card 19 does not have an availablestorage space large enough to store a captured original image, a part orall of the derivative images may be erased.

[0240] In this case, it is possible to secure the storage space for theoriginal image.

[0241] <<Third Embodiment>>

[0242] A third embodiment is an embodiment of an electronic cameracorresponding to the inventions of claims 14 and 18.

[0243] Note that the configuration of the electronic camera in the thirdembodiment is the same as that in the first embodiment (FIG. 1 and FIG.2), and therefore, the configuration description thereof will be omittedhere.

[0244] [Relation with the Invention]

[0245] Hereinafter, the relation between the invention and the thirdembodiment will be explained. It should be noted that the relation hereonly illustrates one interpretation for reference and is not intended tolimit the present invention more than necessary.

[0246] An imaging unit described in the claims corresponds to an imagesensor 13, a timing generator 13 a, an image processing unit 14, an A/Dconverting unit 15, and a DSP 16.

[0247] A derivative image generating unit described in the claimscorresponds to ‘a function of generating a derivative image’ of an MPU21 (or the DSP 16).

[0248] A transfer unit described in the claims corresponds to aninterface 32.

[0249] A display unit described in the claims corresponds to the MPU 21and a liquid crystal display unit 31.

[0250] [Description on Operation of Full Screen Display Mode]

[0251]FIG. 7 is a flowchart explaining the operation performed in a fullscreen display mode in the third embodiment. Hereinafter, the operationin the full screen display mode will be explained following the steps inFIG. 7.

[0252] Step S101: A user turns a command dial 25 first to select areproduction mode. The user further operates a display switch button 27as required to select the full screen display mode.

[0253] When the full screen display mode is thus selected, the MPU 21selects a frame number for the full screen display.

[0254] After image capturing, for example, the MPU 21 selects the lastframe number (in other words, a frame number captured most recently) asthe frame number for the full screen display.

[0255] After image reproduction, for another example, the MPU 21 selectsa most recently reproduced frame number as the frame number for the fullscreen display.

[0256] Step S102: The MPU 21 generates a file name of an original imagecorresponding to the selected frame number based on the selected framenumber and a file name rule.

[0257] When the file name rule of original images is, for example,“DSCN * * * .jpg”, the MPU 21 inserts the frame number in the serialnumber “ * * * ” to generate the file name of the original image.

[0258] Step S103: The MPU 21 reads out a compressed file of the originalimage from a memory card 19 based on the generated file name and storesthis compressed file in a buffer memory 18. After expanding thiscompressed file, the DSP 16 converts the resolution thereof according tothe screen size of the liquid crystal display unit 31 and stores thisconverted file in a frame memory 30. The liquid crystal display unit 31displays on the full screen the original image (the one converted inaccordance with the screen size of a monitor screen) in this framememory 30.

[0259] Step S104: The MPU 21 determines whether or not the displayedoriginal image has a derivative image for transfer.

[0260] When a file name rule of derivative images is, for example,“SSCN * * * .jpg”, the MPU 21 changes an initial letter of the file nameof the original image from “D” to “S” to generate a file name of thederivative image. The MPU 21 searches the memory card 19 for this filename of the derivative image to determine whether or not the originalimage has the derivative image.

[0261] When the original image has the derivative image here, the MPU 21shifts its operation to Step S105.

[0262] On the other hand, when the corresponding derivative image doesnot exist, the MPU 21 shifts its operation to Step S106.

[0263] Step S105: The MPU 21 overlappingly displays an informationdisplay indicating that “a derivative image exists” as shown in FIG. 9on the liquid crystal display unit 31 via the frame memory 30.

[0264] After such information display, the MPU 21 shifts its operationto Step S106.

[0265] Step S106: The MPU 21 waits for a user's key operation with thisfull screen display on (FIG. 9).

[0266] When the user presses down a left key 23 c or a right key 23 dhere, the MPU 21 shifts its operation to Step S107.

[0267] On the other hand, when the user presses down a derivative imagegenerating button 29, the MPU 21 shifts its operation to Step S108.

[0268] Step S107: If the right key 23 d is pressed down here, the MPU 21cyclically moves the frame number for the full screen display oneforward.

[0269] On the other hand, if the left key 23 c is pressed down, the MPU21 cyclically moves the frame number for the full screen display onebackward.

[0270] After thus changing the frame number, the MPU 21 shifts itsoperation back to Step S102.

[0271] Step S108: The MPU 21 displays the following confirmation menuoverlappingly on a display image on the liquid crystal display unit 31.

[0272] Header “Generate a derivative image?”

[0273] Option {circle over (1)} Yes (default option)

[0274] Option {circle over (2)} No

[0275] Option {circle over (3)} Change reduction size

[0276] Step S109: The MPU 21 monitors the user's operation to a crossbutton 23 to receive the selection from the above options {circle over(1)} to {circle over (3)}.

[0277] Specifically, the user hits the right key 23 d once, determiningthe selection of the option {circle over (1)}. In this case, the MPU 21shifts its operation to Step S112.

[0278] The user hits the right key 23 d once after hitting a down key 23b once, determining the selection of the option {circle over (2)}. Inthis case, the MPU 21 cancels generating a new derivative image andshifts its operation back to Step S106.

[0279] On the other hand, the user hits the right key 23 d once afterhitting the down key 23 b twice, determining the selection of the option{circle over (3)}. In this case, the MPU 21 shifts its operation to StepS110.

[0280] Step S110: The MPU 21 additionally displays the followingconfirmation menu on the display image on the liquid crystal displayunit 31.

[0281] Header “Change reduction size”

[0282] Option {circle over (1)} 640×480 (default at the shipping time)

[0283] Option {circle over (2)} 320×240

[0284] Option {circle over (3)} 160×120

[0285] Option {circle over (4)} 96×72

[0286] Step S111: The MPU 21 monitors the user's operation to the crossbutton 23 to receive the selection of the image size (reduction size) ofthe derivative image. The MPU 21 uses the image size selected here as adefault thereafter. After this operation, the MPU 21 shifts itsoperation back to Step S108.

[0287] Step S112: The MPU 21 reads out from the memory card 19 thecompressed file of the original image currently displayed on the liquidcrystal display unit 31 to store this compressed file in the buffermemory 18. The DSP 16 expands this compressed file to develop theoriginal image in the buffer memory 18 (incidentally, when the expandedimage in Step S103 still exists in the buffer memory 18, this expandedimage is preferably used to omit the original image expandingoperation).

[0288] The MPU 21 (or the DSP 16) converts the resolution of theoriginal image in this buffer memory 18 to the default image size togenerate a derivative image.

[0289] The DSP 16 compresses this derivative image to, for example,about {fraction (1/16)} irrespective of the compressibility of theoriginal image.

[0290] The MPU 21 copies header information of the original image andappends it to compressed data of the derivative image to generate acompressed file in an EXIF format.

[0291] Further, the MPU 21 replaces the initial letter of the file name“DSCN * * * .jpg” of the original image with a letter (for example, “S”or the like) according to the image size, and the resultant file name isdefined as a file name of the derivative image.

[0292] The MPU 21 records the file of thus completed derivative image inthe same folder as the original image in the memory card 19.

[0293] After this operation, the MPU 21 shifts its operation back toStep S106.

[0294] Through a series of the operations explained above, the fullscreen display is carried out.

[0295] [Description on Operation of Thumbnail Display Mode]

[0296]FIG. 8 is a flowchart explaining the operation performed in athumbnail display mode.

[0297] Next, the operation in the thumbnail display mode will beexplained following the steps in FIG. 8.

[0298] Step S121: The user turns the command dial 25 first to select thereproduction mode. The user further operates the display switch button27 if necessary to select the thumbnail display mode.

[0299] When the thumbnail display mode is thus selected, the MPU 21decides a frame number at a focus position (an original image for focusselected from a group of thumbnail-displayed images).

[0300] After image capturing, for example, the MPU 21 selects the lastframe number (namely, a frame number most recently captured) as theframe number at the focus position.

[0301] After image reproduction, for another example, the MPU 21 selectsa most recently reproduced frame number as the frame number at the focusposition.

[0302] Step S122: Based on the selected frame number and the file namerule, file names of the group of the original images for the thumbnaildisplay are generated.

[0303] Step S123: The MPU 21 retrieves these file names from the memorycard 19 and sequentially reads out the thumbnail images each stored in aheader of each file. The MPU 21 displays these thumbnail images as alist on the liquid crystal display unit 31 via the frame memory 30.

[0304] Step S124: The MPU 21 determines whether or not each of theoriginal images on the screen has a derivative image based on the filename rule. The MPU 21 displays information indicating that “a derivativeimage exists” on the thumbnail image corresponding to the original imagehaving the derivative image, as shown in FIG. 10.

[0305] Step S125: The MPU 21 waits for a user's key operation with thisthumbnail display on.

[0306] If the user presses down the derivative image generating button29 here, the MPU 21 shifts its operation to Step S126.

[0307] Meanwhile, when the user presses down a cross button 23, the MPU21 shifts its operation to Step S127.

[0308] When the user presses down an enter key, the MPU 21 shifts itsoperation to Step S131.

[0309] Step S126: In case where the derivative image generating button29 is pressed down here, the MPU 21 displays a derivative imagegeneration mark on each of the thumbnail images at the focus positions,as shown in FIG. 10. Further, the MPU 21 adds the frame number of thisfocus position in a derivative image generation schedule list which isprepared on an internal memory. After this operation, the MPU 21 shiftsits operation back to Step S125.

[0310] Step S127: The MPU 21 determines the user's operation to thecross button 23.

[0311] If the user presses the down key 23 b down here, the MPU 21shifts its operation to Step S128.

[0312] On the other hand, when the user presses down the left key 23 cor the right key 23 d, the MPU 21 shifts its operation to Step S129.

[0313] Step S128: The MPU 21 searches for the derivative image of theoriginal image at the focus position, and displays as information imagesize of this derivative image on the thumbnail image at the focusposition (refer to FIG. 10).

[0314] Note that when the original image at the focus position has aplurality of derivative images, the MPU 21 displays the image sizes ofthe derivative images in sequence every time the down key 23 b ispressed down.

[0315] After this operation, the MPU 21 shifts its operation back toStep S125.

[0316] Step S129: When the right key 23 d is pressed down, the MPU 21moves the focus position forward by one frame.

[0317] On the other hand, when the left key 23 c is pressed down, theMPU 21 moves the focus position backward by one frame.

[0318] Step S130: In accordance with such shift in the focus position,the MPU 21 determines whether or not the focus position shifts to theoutside of a thumbnail display range.

[0319] When the focus position shifts within the thumbnail display rangehere, the MPU 21 shifts its operation back to Step S125.

[0320] On the other hand, when the focus position shifts to the outsideof the thumbnail display range, the MPU 21 shifts its operation back toStep S122 and updates the thumbnail display.

[0321] Step S131: When the enter key 29 a is pressed down, the MPU 21overlappingly displays the following confirmation menu on the liquidcrystal display unit 31.

[0322] Header “Generate a derivative image?”

[0323] Option {circle over (1)} Yes (default option)

[0324] Option {circle over (2)} No

[0325] Option {circle over (3)} Change reduction size

[0326] Step S132: The MPU 21 monitors the user's operation to the crossbutton 23 to receive the selection from the above options {circle over(1)} to {circle over (3)}.

[0327] When the option {circle over (1)} is selected here, the MPU 21shifts its operation to Step S135.

[0328] When the option {circle over (2)} is selected, the MPU 21 cancelsgenerating a new derivative image and shifts its operation back to StepS125.

[0329] On the other hand, when the option {circle over (3)} is selected,the MPU 21 shifts its operation to Step S133.

[0330] Step S133: The MPU 21 additionally displays the followingconfirmation menu on the display image on the liquid crystal displayunit 31.

[0331] Header “Change reduction size”

[0332] Option {circle over (1)} 640×480 (default at the shipping time)

[0333] Option {circle over (2)} 320×240

[0334] Option {circle over (3)} 160×120

[0335] Option {circle over (4)} 96×72

[0336] Step S134: The MPU 21 monitors the user's operation to the crossbutton 23 to receive the selection of the image size (reduction size) ofthe derivative image. The MPU 21 uses the image size selected here as adefault thereafter. After this operation, the MPU 21 shifts itsoperation back to Step S131.

[0337] Step S135: The MPU 21 sequentially generates the derivativeimages from the original images with the generation mark (the originalimages listed in the derivative image generation schedule list) andsequentially records these derivative images in the memory card 19.

[0338] After this operation, the MPU 21 shifts its operation back toStep S125.

[0339] [Effect and so on of Third Embodiment]

[0340] As described above, in the third embodiment, the original imageand the derivative image are discriminated based on the file name ruleand only the original image is displayed on the liquid crystal displayunit 31. This makes it possible to surely prevent the user from beingconfused at image management since there is no case where the originalimage and the derivative image being the same image are displayedtogether.

[0341] Further, only the original image is an object of display so thatthe number of images to be displayed is decreased.

[0342] This enables the user to quickly find a target image (picture)from a small number of images.

[0343] Moreover, also in the thumbnail display mode, only the originalimages are displayed and thus the original images and the derivativeimages are not displayed concurrently on the screen. This can surelyprevent the user from being confused at the image management because theoriginal image and the derivative image being the same image are bothpresent on the screen.

[0344] Next, another embodiment will be explained.

[0345] <<Fourth Embodiment>>

[0346] A fourth embodiment is an embodiment of an electronic cameracorresponding to the inventions of claims 15 to 19.

[0347] Note that the configuration of the electronic camera in thefourth embodiment is the same as that in the third embodiment (FIG. 1and FIG. 2), and therefore, the configuration description thereof willbe omitted here. Further, description on the same operations as those ofthe third embodiment (the operation in the thumbnail display mode and soon) will be also omitted in order to avoid repeated description.

[0348] [Relation with the Invention]

[0349] Hereinafter, the relation between the inventions and the fourthembodiment will be explained. It should be noted that the relation hereonly illustrates one interpretation for reference and is not intended tolimit the present invention more than necessary.

[0350] An imaging unit described in the claims corresponds to an imagesensor 13, a timing generator 13 a, an image processing unit 14, an A/Dconverting unit 15, and a DSP 16.

[0351] A derivative image generating unit described in the claimscorresponds to ‘a function of generating a derivative image’ of an MPU21 (or the DSP 16).

[0352] A transfer unit described in the claims corresponds to aninterface 32.

[0353] A display unit described in the claims corresponds to the MPU 21and a liquid crystal display unit 31.

[0354] A slide display unit described in the claims corresponds to theMPU 21 and the liquid crystal display unit 31.

[0355] [Description on Operation of Full Screen Display Mode]

[0356]FIG. 11 is a flowchart explaining the operation performed in afull screen display mode in the fourth embodiment. In this FIG. 11, thesame step numbers are assigned to the same operations as those in thethird embodiment (FIG. 7), and repeated description thereof will beomitted here.

[0357] The operation in the full screen display mode shown in FIG. 11 ischaracterized in that Steps S141 to S143 are newly added. Hereinafter,this added part will be explained.

[0358] Step S141: The MPU 21 reads out from a memory card 19 a fileproperty of an original image which is to be displayed, and determineswhether or not this original image is set as non-display.

[0359] When the original image is set as non-display here, the MPU 21shifts its operation to Step S142.

[0360] On the other hand, when the original image is not set asnon-display (when the display thereof is permitted), the MPU 21 shiftsits operation to Step S103.

[0361] Step S142: The MPU 21 cyclically moves a frame number which is tobe displayed, by one frame forward and so controls that the originalimage (and a derivative image) set as non-display is not displayed onthe screen. After this operation, the MPU 21 shifts its operation backto Step S102.

[0362] Step S143: When a down key 23 b is pressed down in Step S106, theMPU 21 replaces an initial letter of a file name “DSCN * * * .jpg” ofthe original image with a letter (for example, “S” or the like)according to the image size to generate a file name of the derivativeimage. The MPU 21 searches the memory card 19 for this derivative image.Upon finding this derivative image, the MPU 21 reads out this derivativeimage from the memory card 19, and displays a display 42 of thisderivative image overlappingly on a full screen display 41 of theoriginal image, as shown in FIG. 12. At this time, the MPU 21 alsodisplays an icon 43 as information showing the image size of thisderivative image.

[0363] Note that when the down key 23 b is pressed down a plurality oftimes, the MPU 21 sequentially displays a plurality of derivative imagesin the descending order of the image size. FIG. 12 shows a state inwhich the plural derivative images are displayed by this operation in anesting way.

[0364] [Description on Operation of Slide Display Mode]

[0365]FIG. 13 is a flowchart explaining the operation performed in aslide display mode in the fourth embodiment. Hereinafter, the operationin the slide display mode will be explained following the steps in FIG.13.

[0366] Step S161: A user first turns a command dial 25 to select areproduction mode. The user further operates a display switch button 27as required to select the slide display mode.

[0367] When the slide display mode is thus selected, the MPU 21 selectsan initial frame number of slide display from the memory card 19, andsubstitutes this frame number in a frame number N.

[0368] Step S162: A file name of the original image corresponding to theframe number N is generated based on the frame number N and a file namerule.

[0369] When the file name rule of original images is, for example,“DSCN * * * .jpg”, the MPU 21 inserts the frame number in the serialnumber “ * * * ” to generate the file name of the original image.

[0370] Step S163: The MPU 21 obtains information on a file property fromthe memory card 19 based on the generated file name of the originalimage and determines whether or not the original image is set asnon-display.

[0371] When the original image is set as non-display here, the MPU 21shifts its operation to Step S164.

[0372] On the other hand, the original image is not set as non-display(when the display thereof is permitted), the MPU 21 shifts its operationto Step S165.

[0373] Step S164: The MPU 21 moves the frame number to be displayed byone frame forward cyclically and so controls that the original image setas non-display is not displayed on the screen. After this operation, theMPU 21 shifts its operation back to Step S 162.

[0374] Step S165: The MPU 21 reads out a compressed file of the originalimage from the memory card 19 based on the generated file name of theoriginal image and stores this compressed file in a buffer memory 18.After expanding this compressed file, the DSP 16 converts the resolutionthereof according the screen size of the liquid crystal display unit 31and stores the converted file in a frame memory 30. The liquid crystaldisplay unit 31 displays the original image (the one converted accordingto the screen size of a monitor screen) stored in this frame memory 30.

[0375] Step S166: The MPU 21 determines whether or not the originalimage on display has a derivative image for transfer.

[0376] When the original image on display has the derivative image here,the MPU 21 shifts its operation to Step S167.

[0377] On the other hand, when the original image on display does nothave the derivative image, the MPU 21 shifts its operation to Step S168.

[0378] Step S167: The MPU 21 overlappingly displays an informationdisplay indicating that “a derivative image exists” on the liquidcrystal display unit 31 via the frame memory 30. After such informationdisplay, the MPU 21 shifts its operation to Step S168.

[0379] Step S168: The MPU 21 waits for the elapse of a slide displaytime corresponding to one frame and shifts its operation to Step S169.

[0380] Step S169: The MPU 21 determines whether or not the current framenumber N is the last frame number in the memory card 19.

[0381] When the current frame number N is different from the last framenumber, the MPU 21 shifts its operation back to Step S164.

[0382] On the other hand, when the current frame number N is the lastframe number, the slide display operation is finished.

[0383] [Effect and so on of Fourth Embodiment]

[0384] As described above, in the fourth embodiment, the informationdisplay on the image size of the derivative image is displayed as shownin FIG. 12. This enables a user to appropriately distinguish theoriginal image and the derivative image being the same image based onthe information on the image size.

[0385] Further, in the fourth embodiment, when the down key 23 b ispressed down while the original image is displayed on the full screen,the derivative images are displayed in the descending order of the imagesize. In this case, the user can appropriately distinguish the originalimage and the derivative image based on the display order.

[0386] Moreover, in the fourth embodiment, when the original image isset as non-display, the derivative image is also set as non-displaytogether with the original image. Therefore, the user need notseparately set the derivative image as non-display, which can save theuser's time and labor.

[0387] Further, in the fourth embodiment, the original image and thederivative image are discriminated based on the file name rule and onlythe original image is displayed in the slide display mode. Therefore,the original image and the derivative image being the same image are notredundantly and repeatedly displayed, which enables the user to lookthrough a series of images in as short a time as possible.

[0388] <<Fifth Embodiment>>

[0389] A fifth embodiment is an embodiment of an electronic cameracorresponding to the inventions of claims 20 to 24.

[0390] Note that since the configuration of the electronic camera in thefifth embodiment is the same as that in the first embodiment (FIG. 1 andFIG. 2), the configuration description thereof will be omitted here.

[0391] [Relation with the invention]

[0392] Hereinafter, the relation between the inventions and the fifthembodiment will be explained. It should be noted that the relation hereonly illustrates one interpretation for reference and is not intended tolimit the present invention more than necessary.

[0393] An imaging unit described in the claims corresponds to an imagesensor 13, a timing generator 13 a, an image processing unit 14, an A/Dconverting unit 15, and a DSP 16.

[0394] A derivative image generating unit described in the claimscorresponds to “a function of generating a derivative image” of an MPU21 (or the DSP 16).

[0395] A transfer setting unit described in the claims corresponds to ‘afunction of setting a flag on an image’ of the MPU 21.

[0396] A transfer unit described in the claims corresponds to aninterface 32.

[0397] An erase unit described in the claims corresponds to “a functionof erasing an image in a memory card 19” of the MPU 21.

[0398] [User Interface in Full Screen Display Mode]

[0399]FIG. 14 is a flowchart explaining the operation performed in afull screen display mode in the fifth embodiment. Hereinafter, theoperation in the full screen display mode will be explained followingthe steps in FIG. 14.

[0400] Step S201: A user first turns a command dial 25 of an electroniccamera 11 to select a reproduction mode. The user further operates adisplay switch button 27 as required to select the full screen displaymode.

[0401] When the full screen display mode is thus selected, the MPU 21selects a frame number of an image for the full screen display.

[0402] After image capturing, for example, the MPU 21 selects the lastframe number (namely, a frame number most recently captured) as theframe number for the full screen display.

[0403] After the image reproduction, for example, the MPU 21 selects amost recently reproduced frame number as the frame number for the fullscreen display.

[0404] Step S202: The MPU 21 generates a file name of an original imagecorresponding to the selected frame number based on the selected framenumber and a file name rule.

[0405] When the file name rule of original images is, for example,“DSCN: * * * .jpg”, the MPU 21 inserts the frame number in place of theserial number “ * * * ” to generate the file name of the original name.

[0406] Step S203: The MPU 21 reads out a compressed file of the originalimage from the memory card 19 based on the generated file name andstores this compressed file in a buffer memory 18. After expanding thiscompressed file, the DSP 16 converts the resolution according to thescreen size of a liquid crystal display unit 31, and stores thisconverted file in a frame memory 30. The liquid crystal display unit 31displays on the full screen the original image (the one converted inaccordance with the screen size of a monitor screen) stored in thisframe memory 30.

[0407] Step S204: With this full screen display, the MPU 21 determines akey operation to a cross button 23 by a user.

[0408] When the user presses down a left key 23 c or a right key 23 dhere, the MPU 21 shifts its operation to Step S205.

[0409] When the user presses down a down key 23 b, the MPU 21 shifts itsoperation to Step S206.

[0410] In other cases, the MPU 21 shifts its operation to Step S208.

[0411] Step S205: When the right key 23 d is pressed down, the MPU 21moves the frame number for the full screen display one forwardcyclically.

[0412] On the other hand, when the left key 23 c is pressed down, theMPU 21 moves the frame number for the full screen display one backwardcyclically.

[0413] After thus changing the frame number, the MPU 21 shifts itsoperation back to Step S202.

[0414] Step S206: The MPU 21 determines whether or not the originalimage on display has a derivative image.

[0415] When a file name rule of derivative images is, for example,“SSCN * * * .jpg”, the MPU 21 changes an initial letter of the file nameof the original image from “D” to “S” to generate a file name of thederivative image. The MPU 21 searches the memory card 19 for this filename of the derivative image, thereby judging whether or not theoriginal image has the derivative image.

[0416] When the original image has the derivative image here, the MPU 21shifts its operation to Step S207.

[0417] On the other hand, the corresponding derivative image does notexist, the MPU 21 shifts its operation back to Step S204.

[0418] Step S207: The MPU 21 reads out from the memory card 19 thederivative image which is generated from the original image on display.The MPU 21 displays a display 42 of this derivative image overlappinglyon a full screen display 41 of the original image, as shown in FIG. 12.At this time, the MPU 21 also displays as information an icon 43indicating the image size of this derivative image together.

[0419] Note that when the down key 23 b is pressed down a plurality oftimes, the MPU 21 sequentially displays a plurality of derivative imagesin the descending order of the image size. FIG. 12 shows a state inwhich the plural derivative images are displayed by this operation in anesting way.

[0420] After this display operation to the derivative image, the MPU 21shifts its operation back to Step S204.

[0421] Step S208: Further, the MPU 21 determines other user's keyoperations.

[0422] When the MPU 21 recognizes the key operation to a transfer button28 here, the MPU 21 shifts its operation to Step S209.

[0423] When the MPU 21 recognizes the key operation to an erase button29 b, the MPU 21 shifts its operation to Step S213.

[0424] In other cases, the MPU 21 shifts its operation to Step S221.

[0425] Step S209: The MPU 21 determines whether or not the originalimage on display has a derivative image.

[0426] When the original image has the derivative image here, the MPU 21shifts its operation to Step S210.

[0427] On the other hand, when the corresponding derivative image doesnot exist, the MPU 21 shifts its operation to Step S211.

[0428] Step S210: The MPU 21 determines whether or not the originalimage on display has any print information (specification of a frame tobe printed, the number of sheets to be printed, and so on) specified inDPOF (abbreviation of Digital Print Order Format) and the like.

[0429] When the original image on display has the print information, theMPU 21 shifts its operation to Step S211.

[0430] On the other hand, when the original image on display does nothave any print information, the MPU 21 shifts its operation to StepS212.

[0431] Step S211: The MPU 21 sets a flag on the original image ondisplay. This flag is set in such a manner, for example, that the MPU 21writes information indicating a transfer candidate in a header or thelike of an image file. Another example of how the flag is set is thatthe MPU 21 adds an identifier (file name or the like) of the image to atransfer candidate list on an internal memory.

[0432] After the setting operation, the MPU 21 shifts its operation backto Step S204.

[0433] Step S212: The MPU 21 sets the flag not on the original image ondisplay but on the derivative image that the original image has.

[0434] After this setting operation, the MPU 21 shifts its operationback to Step S204.

[0435] Step S213: The MPU 21 determines whether or not the derivativeimage is displayed on the screen.

[0436] When the derivative image is displayed here as shown in FIG. 12,the MPU 21 shifts its operation to Step S218.

[0437] On the other hand, when only the original image is displayed onthe screen, the MPU 21 shifts its operation to Step S214.

[0438] Step S214: The MPU 21 erases the original image on display fromthe memory card 19.

[0439] Step S215: The MPU 21 determines whether or not the erasedoriginal image had a derivative image.

[0440] When the erased original image had the derivative image here, theMPU 21 shifts its operation to Step S216.

[0441] On the other hand, when the erased original image does not havethe derivative image, the MPU 21 shifts its operation to Step S217.

[0442] Step S216: The MPU 21 erases the derivative image that theoriginal image had. Further, when the flag has been set on thisderivative image, the MPU 21 removes the flag.

[0443] Note that when the flag is set as information in the header ofthe image file, removal of this flag is done concurrently with the fileerase of the derivative image. Also, when setting the flag is managedaccording to the transfer candidate list on the internal memory of theMPU 21, the removal of the flag is done at the same time as theidentifier of an image as a transfer candidate is removed from thistransfer candidate list.

[0444] Step S217: The MPU 21 moves the frame number of the originalimage to be displayed by one frame backward in accordance with the eraseof the original image. Thereafter, the MPU 21 shifts its operation backto Step S202 and updates the full screen display.

[0445] Step S218: The MPU 21 determines whether or not a flag is set onthe derivative image displayed on the utmost front window of the screen.

[0446] When this derivative image has the flag set here, the MPU 21shifts its operation to Step S219.

[0447] On the other hand, when this derivative image does not have theflag set, the MPU 21 shifts its operation to Step S220.

[0448] Step S219: The MPU 21 sets the flag on the original image fromwhich this derivative image is generated. Note that when one originalimage has a plurality of derivative images, the MPU 21 sets the flag ona derivative image having the second largest image size next to thederivative image displayed on the utmost front window.

[0449] Step S220: The MPU 21 erases from the memory card 19 thederivative image displayed on the utmost front window. Further, in acase where this derivative image has a flag, the MPU 21 removes the flagat the same time.

[0450] After this operation, the MPU 21 shifts its operation back toStep S202 and updates the full screen display.

[0451] Step S221: The MPU 21 determines a key operation to a derivativeimage generating button 29 by a user.

[0452] When the MPU 21 recognizes the user's key operation to thederivative image generating button 29 here, the MPU 21 shifts itsoperation to Step S222.

[0453] On the other hand, when the MPU 21 does not recognize the keyoperation to the derivative image generating button 29, the MPU 21shifts its operation back to Step S204.

[0454] Step S222: The MPU 21 reads out from the memory card 19 thecompressed file of the original image currently displayed and storesthis compressed file in the buffer memory 18. The DSP 16 expands thiscompressed file to develop the original image stored in the buffermemory 18 (incidentally, when the expanded image in Step S203 stillexists in the buffer memory 18, it is preferable to use this image,thereby omitting the original image expanding operation).

[0455] The MPU 21 (or the DSP 16) converts the resolution of thisoriginal image in the buffer memory 18 to generate a derivative image.

[0456] The DSP 16 compresses this derivative image to, for example,about {fraction (1/16)} irrespective of the compressibility of theoriginal image.

[0457] The MPU 21 copies header information of the original image andappends it to compressed data of the derivative image to generate acompressed file in an EXIF format.

[0458] Further, the MPU 21 replaces the initial letter of the file name“DSCN * * * .jpg” of the original image with a letter (for example, “S”or the like) according to the image size to generate a file name of thederivative image.

[0459] The MPU 21 records thus generated file of the derivative image inthe same folder as the original image in the memory card 19.

[0460] Step S223: The MPU 21 determines whether or not the flag is seton the original image currently on display.

[0461] When this original image has the flag set here, the MPU 21 shiftsits operation to Step S224.

[0462] On the other hand, when this original image does not have theflag set, the MPU 21 shifts its operation back to Step S204.

[0463] Step S224: The MPU 21 removes the flag on the original imagecurrently on display, and sets the flag on a newly generated derivativeimage.

[0464] After this operation, the MPU 21 shifts its operation back toStep S204.

[0465] Through a series of the operations explained above, the fullscreen display is carried out.

[0466] [User Interface in Thumbnail Display Mode]

[0467]FIG. 15 is a flowchart explaining the operation performed in athumbnail display mode.

[0468] Next, the operation in the thumbnail display mode will beexplained following the steps in FIG. 15.

[0469] Step S241: The user first turns the command dial 25 of theelectronic camera 11 to select the reproduction mode. The user furtheroperates the display switch button 27 as required to select thethumbnail display mode.

[0470] When the thumbnail display mode is thus selected, the MPU 21determines a frame number of a focus position (an original imageselected for focusing among a group of images displayed in the thumbnaildisplay mode).

[0471] After image capturing, for example, the MPU 21 selects the lastframe number (that is, a frame number most recently captured) as theframe number of the focus position.

[0472] After image reproduction, for another example, the MPU 21 selectsa most recently reproduced frame number as the frame number of the focusposition.

[0473] Step S242: The MPU 21 generates file names of a group of originalimages for the thumbnail display in sequence based on the selected framenumber and the file name rule.

[0474] Step S243: The MPU 21 retrieves these file names from the memorycard 19 and sequentially reads out thumbnail images stored in a headeror the like of each file. The MPU 21 stores these thumbnail images inthe frame memory 30, and displays these thumbnail images as a list onthe liquid crystal display unit 31, as shown in FIG. 16. At this time,the image at the focus position is highlighted (using a dotted frame orthe like as shown in FIG. 16).

[0475] Step S244: The MPU 21 determines whether or not the originalimage on the screen has a derivative image based on the file name rule.As for the original image having the derivative image, the MPU 21displays information indicating that “a derivative image exists” on acorresponding thumbnail image, as shown in FIG. 16.

[0476] Step S245: The MPU 21 determines the user's key operation to thecross button 23 in this thumbnail display state.

[0477] When the user presses down the down key 23 b here, the MPU 21shifts its operation to Step S246.

[0478] When the user presses down the left key 23 c or the right key 23d, the MPU 21 shifts its operation to Step S247.

[0479] In other cases, the MPU 21 shifts its operation to Step S249.

[0480] Step S246: The MPU 21 retrieves the derivative image of theoriginal image at the focus position, and displays information on theimage size of this derivative image on the thumbnail image at the focusposition (refer to FIG. 16).

[0481] Note that when the original image at the focus position hasplural derivative images, the MPU 21 displays the image sizes of thederivative images in the descending order every time the down key 23 bis pressed down.

[0482] After this operation, the MPU 21 shifts its operation back toStep S245.

[0483] Step S247; When the right key 23 d is pressed down, the MPU 21moves the focus position by one frame forward.

[0484] On the other hand, when the left key 23 c is pressed down, theMPU 21 moves the focus position by one frame backward.

[0485] Step S248: In accordance with such shift of the focus position,the MPU 21 performs scroll shifting of a thumbnail view so as to keepthe focus position within the screen.

[0486] After this operation, the MPU 21 shifts its operation back toStep S245.

[0487] Step S249: The MPU 21 further determines a user's operation toother keys.

[0488] When the MPU 21 recognizes the key operation to the derivativeimage generating button 29 here, the MPU 21 shifts its operation to StepS250.

[0489] When the MPU 21 recognizes the key operation to the erase button29 b, the MPU 21 shifts its operation to Step S251.

[0490] In other cases, the MPU 21 shifts its operation to Step S252.

[0491] Step S250: When the derivative image generating button 29 is thuspressed down, the MPU 21 displays a derivative image generation mark onthe thumbnail image at the focus position. Further, the MPU 21 adds theframe number of this focus position to a derivative image generationschedule list which is prepared on the internal memory. After thisoperation, the MPU 21 shifts its operation back to Step S245.

[0492] Step S251: When the erase button 29 b is pressed down here, theMPU 21 displays a derivative image erase mark on the thumbnail image atthe focus position. Further, the MPU 21 adds the frame number of thisfocus position to a derivative image erase schedule list which isprepared on the internal memory. After this operation, the MPU 21 shiftsits operation back to Step S245.

[0493] Step 252: The MPU 21 further determines the user's operation toother keys.

[0494] When the MPU 21 recognizes the key operation to the transferbutton 28 here, the MPU 21 shifts its operation to Step S253.

[0495] Meanwhile, when the MPU 21 recognizes the key operation to anenter key 29 a, the MPU 21 shifts its operation to Step S257.

[0496] In other cases, the MPU 21 shifts its operation back to StepS245.

[0497] Step S253: The MPU 21 determines whether or not the originalimage at the focus position has a derivative image.

[0498] When the original image has the derivative image here, the MPU 21shifts its operation to Step S254.

[0499] On the other hand, when no corresponding derivative image exists,the MPU 21 shifts its operation to Step S255.

[0500] Step S254: The MPU 21 determines whether or not the originalimage at the focus position has any print information (specification ofa frame to be printed, the number of sheets to be printed, and so on)which is specified in DPOF (abbreviation of Digital Print Order Format)or the like.

[0501] When the original image has the print information here, the MPU21 shifts its operation to Step S255.

[0502] On the other hand, when the original image on display does nothave any print information, the MPU 21 shifts its operation to StepS256.

[0503] Step S255: The MPU 21 sets the flag on the original image at thefocus position.

[0504] After this setting operation, the MPU 21 shifts its operationback to Step S245.

[0505] Step S256: The MPU 21 sets the flag not on the original image atthe focus position but on the derivative image that this original imagehas.

[0506] After this setting operation, the MPU 21 shifts its operationback to Step S245.

[0507] Step S257: The MPU 21 selects the original image with thederivative image erase mark (the original image listed in the derivativeimage generation schedule list) and erases this original image togetherwith the derivative image. Note that when the derivative image has theflag, the MPU 21 removes this flag as well.

[0508] Step S258: The MPU 21 selects the original images with thederivative image generation mark (the original images listed in thederivative image generation schedule list) to generate the derivativeimages in sequence and records them in sequence on the memory card 19.Note that when the original image has the flag, the MPU 21 removes theflag from the original image and sets the flag on a newly generatedderivative image.

[0509] After this operation, the MPU 21 shifts its operation back toStep S245.

[0510] Through a series of the operations explained above, the operationduring the thumbnail display is carried out.

[0511] [Description on Image Transfer Operation]

[0512] Next, the outline of an image transfer operation by theelectronic camera 11 will be explained.

[0513] The user first connects the interface 32 of the electronic camera11 to an external transfer destination via an appropriate transfer route(a cable, a wireless LAN, an Internet terminal, and the like).

[0514] The user turns a command dial 25 in this state to set theelectronic camera 11 in a transfer mode.

[0515] The MPU 21 waits for a user's operation to a transfer button 28according to such a transfer mode. When the user presses down thetransfer button 28, the MPU 21 selects a file of an image having theflag, and transfers this image to the external transfer destinationaccording to a predetermined protocol.

[0516] [Effect and so on of Fifth Embodiment]

[0517] As explained above, in generating the derivative image from theoriginal image having the flag, the electronic camera 11 removes theflag from the original image and sets the flag on the derivative image(refer to Steps S222 to S224 in FIG. 14 and Step 258 in FIG. 15).

[0518] This enables the user to freely set the flag on the originalimage and the derivative image by a two-step operation of {circle over(1)} setting the flag on the original image and {circle over (2)}generating the derivative image from the original image.

[0519] Further, when the original image having the flag set on has thederivative image, the electronic camera 11 does not set the flag on thisoriginal image but sets the flag on the derivative image (refer to StepsS209 to S212 in FIG. 14 and Steps S253 to S256 in FIG. 15).

[0520] This enables the user to freely allot the flag to the originalimage and the derivative image by a two-step operation of {circle over(3)} generating the derivative image from the original image and {circleover (4)} setting the flag on the original image.

[0521] Since these operations are all intended for the original image,the user need not directly deal with the derivative image in spite thatthe derivative image is actually processed. This enables the user to setthe flag in an intuitive and simple manner, focusing on the operation onthe original image.

[0522] Moreover, in the fifth embodiment, in accordance with the eraseof the original image, the derivative image generated from this originalimage is erased, and further, the flag on this derivative image is alsoremoved (refer to Steps S214 to S216 in FIG. 14 and Step S257 in FIG.15). Consequently, the removal of the flag of the derivative image andthe erase of the derivative image can be carried out at the same time byonly a single operation of erasing the original image. As a result,unnecessary image files in the memory card 19 can be easily erased.

[0523] Further, in the fifth embodiment, when the derivative imagehaving the flag is erased, the flag is returned to the original imagefrom which the derivative image is generated (refer to Steps S218 toS220 in FIG. 14). Therefore, the user only needs to erase the derivativeimage when the user intends to transfer the original image instead ofthe derivative image with the flag. In this case, the flag need not benewly set on the original image, which makes it possible to facilitatethe operation of the electronic camera 11.

[0524] In addition, in the fifth embodiment, as for the original imagehaving the print information (for example, the number of sheets to beprinted, print size, image processing information to be referred to atthe time of printing, and so on), the flag is set on the original imageirrespective of existence or nonexistence of the derivative image (referto Steps S210 to S211 in FIG. 14 and Steps S254 to S255 in FIG. 15).

[0525] For printing use, generally, the original image is more suitablethan the derivative image in view of image quality because the originalimage has abundant image information compared to the derivative imagewith reduced data capacity. Hence, in a case where the original imagehas the print information, the original image is preferentially giventhe flag even when it has derivative images. This results in enhancingthe print image quality with reliability when the images are used forprinting purpose at the external transfer destination.

[0526] <<Additional Comments on Embodiments>>

[0527] Note that in the above-described embodiments the resolution ofthe original image is reduced to generate the derivative image. Thepresent invention, however, is not to be limited thereto. For example,the derivative image is generated by reducing the color of the originalimage.

[0528] Further, in the above-described embodiments, the use of the filename rule and the hierarchical folders establishes the associationsbetween the original image and the derivative image. The presentinvention, however, is not to be limited thereto. For example, the fileassociations between the original image and the derivative image may berecorded by using data such as header information of files and filemanagement information on a recording medium. Further, the originalimage and the derivative image may be discriminated by use of, forexample, header information of files, file management information, imagesize, or the like.

[0529] The present invention may be embodied in other specific formswithout departing from the spirit and essential characteristics thereof.Therefore, the above-described embodiments are to be considered in allrespects only as illustrative and no restrictive. The scope of thepresent invention is to be defined by the scope of the patent claims andis not at all to be restricted by the description in the specification.Further, all modifications and changes which come within the meaning andrange of equivalency of the claims are intended to be embraced in thescope of the present invention.

What is claimed is:
 1. An electronic camera comprising: an imaging unitfor capturing a subject to generate an original image; a derivativeimage generating unit for reducing resolution or color of the originalimage to generate derivative image(s) which is/are used for transfer; arecording unit for recording the original image and the derivative imagethereon such that the original image and the derivative image getassociated with each other; and a transfer unit for transferring thederivative image recorded on said recording unit to an external transferdestination.
 2. The electronic camera according to claim 1, wherein saidrecording unit has a folder in which the original image is recorded, andlower folders being under said folder hierarchically and in which thederivative images are separately recorded depending on their respectiveimage sizes, in order to manage the original image and the derivativeimages in a hierarchical manner.
 3. The electronic camera according toclaim 1, wherein: said transfer unit obtains information on saidexternal transfer destination from said external transfer destination ora user; and said derivative image generating unit determines an imageformat in accordance with the information on said external transferdestination to generate the derivative image according to said imageformat.
 4. The electronic camera according to claim 1, furthercomprising an erase control unit for receiving an erase command for theoriginal image from a user, wherein said recording unit erases theoriginal image in compliance with said erase command, and retrieves anderases the recorded derivative image which is associated with the erasedoriginal image.
 5. The electronic camera according to claim 1, whereinsaid recording unit erases the derivative image which has beentransferred to exterior by said transfer unit.
 6. The electronic cameraaccording to claim 1, further comprising a storage space monitoring unitfor determining an available storage space of said recording unit andfinding a shortage in the available storage space, wherein saidrecording unit erases all or a part of the derivative images when saidstorage space monitoring unit finds the shortage in the storage space.7. The electronic camera according to claim 1, further comprising atransfer control unit for receiving a file transfer command for theoriginal image from a user, wherein said recording unit file-transfersthe original image in compliance with said file transfer command, andretrieves and file-transfers the recorded derivative image which isassociated with the original image.
 8. The electronic camera accordingto claim 1, further comprising a protect control unit for receiving aprotect command for the original image from a user, wherein saidrecording unit sets a protect attribute on the original image incompliance with said protect command, and retrieve the recordedderivative image which is associated with the original image to set aprotect attribute on the derivative image.
 9. The electronic cameraaccording to claim 1, further comprising an original image erase controlunit for receiving only an erase command for the original image from auser, wherein said recording unit erases the original image incompliance with said erase command, and retrieves the recordedderivative image which is associated with the original image and upgradethe retrieved derivative image to the original image.
 10. The electroniccamera according to claim 1, wherein: said imaging unit selectively hasa moving image capture mode in which a subject is captured to generatethe original image as a moving image; and said derivative imagegenerating unit generates the derivative image of the original imagecaptured in said moving image capture mode (namely, the moving image),by reducing resolution or color of one frame of the original imagecaptured in said moving image capture mode.
 11. The electronic cameraaccording to claim 1, wherein: said imaging unit selectively has acontinuous capture mode in which a subject is captured to generate theoriginal image as continuous static images; and said derivative imagegenerating unit generates the derivative image (namely, a plurality ofstatic images) of the original image captured in said continuous capturemode (namely, a plurality of static images), by reducing resolution orcolor of each frame of the original image captured in said moving imagecapture mode.
 12. The electronic camera according to claim 1, furthercomprising a thumbnail generating unit for generating a thumbnail imagefor thumbnail display from the original image and appending thegenerated thumbnail image to the original image, wherein said thumbnailgenerating unit does not append said thumbnail image to the originalimage when the number of pixels of said thumbnail image is equal to orlarger than the number of pixels of the derivative image.
 13. Anelectronic camera, comprising: an imaging unit for capturing a subjectto generate an original image; a derivative image generating unit forreducing resolution or color of the original image to generatederivative image(s) which is/are used for transfer; a recording unit forrecording the original image and the derivative image thereon; atransfer unit for transferring the derivative image recorded on saidrecording unit to an external transfer destination; and a control unitfor erasing from said recording unit the derivative image which has beentransferred to exterior by said transfer unit.
 14. The electronic cameraaccording to claim 1, further comprising a display unit displaying animage or information on the image, wherein said display unitdiscriminates between the original image and the derivative image anddecides the derivative image as non-display.
 15. The electronic cameraaccording to claim 1, further comprising a display unit displaying animage or information on the image, wherein upon displaying thederivative image, said display unit displays information on an imagesize of the derivative image.
 16. The electronic camera according toclaim 1, further comprising a display unit displaying an image orinformation on the image, wherein: said display unit displays thederivative image when a user performs a predetermined operation duringdisplay of the original image; and when a plurality of derivative imagesgenerated from a same original image are present, said display unitdisplays the plurality of derivative images in the order of their imagesizes in compliance with the user's predetermined operation.
 17. Theelectronic camera according to claim 1, further comprising a displayunit displaying an image or information on the image, wherein whendeciding the original image as non-display, said display unit alsodecides, as non-display, the derivative image generated from thenon-display original image.
 18. The electronic camera according to claim1, further comprising a display unit displaying an image or informationon the image, wherein said display unit discriminates between theoriginal image and the derivative image, and does not display theoriginal image and the derivative image on a screen at the same time.19. The electronic camera according to claim 1, further comprising aslide display unit automatically displaying a plurality of images insequence, wherein said slide display unit separates said plurality ofimages into original image(s) and derivative image(s) to automaticallydisplay either of the original image (s) and derivative image(s). 20.The electronic camera according to claim 1, further comprising atransfer setting unit setting a flag on an image designated by a user'sinput, the flag indicating a transfer candidate of said transfer unit,wherein: said transfer unit has a function of transferring the originalimage in addition to a function of transferring the derivative image;and when generating the derivative image from the original image havingthe flag set, said derivative image generating unit removes the flagfrom the original image and sets the flag on the generated derivativeimage.
 21. The electronic camera according to claim 1, furthercomprising a transfer setting unit setting a flag on an image designatedby a user's input, the flag indicating a transfer candidate of saidtransfer unit, wherein: said transfer unit has a function oftransferring the original image in addition to a function oftransferring the derivative image; when an original image designated bythe user's input has a derivative image, said transfer setting unit setsthe flag not on the original image but on the derivative image.
 22. Theelectronic camera according to claim 1, wherein further comprising: atransfer setting unit setting a flag on an image designated by a user'sinput, the flag indicating a transfer candidate of said transfer unit;and an erase unit erasing an image designated by a user's input,wherein: said transfer unit has a function of transferring the originalimage in addition to a function of transferring the derivative image; inresponse to erase of the original image, said transfer setting uniterases the derivative image generated from the erased original image,and removes the flag of the derivative image.
 23. The electronic cameraaccording to claim 1, further comprising: a transfer setting unitsetting a flag on an image designated by a user's input, the flagindicating a transfer candidate of said transfer unit; and an erase uniterasing an image designated by a user's input, wherein: said transferunit has a function of transferring the original image in addition to afunction of transferring the derivative image; when the derivative imagehaving the flag set is erased, said transfer setting unit sets the flagon its original image from which the erased derivative image has beengenerated.
 24. The electronic camera according to claim 1, furthercomprising a transfer setting unit setting a flag on an image designatedby user's input, the flag indicating a transfer candidate of saidtransfer unit, wherein: said transfer unit has a function oftransferring the original image in addition to a function oftransferring the derivative image; said transfer setting unit sets theflag on an original image having print information, irrespective ofwhether or not the original image has a derivative image.